The moment came when Peters questioned whether Labour leader Andrew Little would make it back on Labour's list if it polls poorly.

"If you go from 26 down to 22, that's it. Andrew is not in Parliament. So why would you make these statements, that he's the next leader of the country? Or the leader of the Opposition?"

It is a fascinating insight into his plan for the ultimate power grab.

The Winston Peters plan to become Prime Minister

Labour's vote collapses to 22 percent or lower.

At 22 percent Andrew Little won't make it back on Labour's list. That's because Labour will still win a number of safe electorate seats, and won't have enough vote to bring in even its number one list candidate.

Labour therefore does not have a leader with a mandate from the public on September 24.

Labour is in crisis and also has to start its own laborious leadership selection process, which will take several weeks.

But there is still a kingmaker scenario, with Labour/Greens/NZ First still having the numbers to form a Government.

With Labour having no leader, Winston Peters puts forward a combination that with him as Prime Minister. There is a joint policy agenda with concessions for all sides. Labour MPs would be in senior roles like Finance, and Green MPs would also get top jobs.

Labour and the Greens can either take that deal - or Winston Peters goes into Government with National and they are out of power for three more years.

Labour and the Greens accept the Peters plan - and Winston Peters is Prime Minister of New Zealand.

This is obviously an outside chance of happening, but it is not impossible.

It is made much more likely the more power Peters has - for example in a "political earthquake" scenario where he manages to overtake Labour (eg. NZ First 21 percent, Labour 20 percent) - as the most popular opposition party he would obviously have an outright mandate to be Prime Minister of the NZ First/Labour/Green bloc.

Peters knows all this. Even getting NZ First to a record 15 percent result, bringing in 20 MPs, making it a much bigger party than the Greens, and perhaps sweeping Whangarei as well as Northland would enhance his mandate as the "alternative PM".

The key for Peters is to make the case as compelling as possible - Little needs to go, and NZ First needs to get the best result possible.

Right now, we are seeing Labour's vote collapsing and NZ First taking it, according to Labour's pollsters UMR.

Peters is not taking votes from National - yet. He doesn't actually need to - on many polls already just a reorganisation of the "change the Government" vote is enough to get him there. This has to be a real worry for Labour, as taking them down is critical to Peters achieving his life's goal - he is coming for them.

Peters' tour of the regions was all about attacking National - which is all about taking potential Labour voters. When he starts attacking Labour and the Greens - which he will - that's when he will start trying to take National's vote. But his priority right now is Labour.

I have always doubted the "Winston as PM" scenario, especially the "shared Prime Minister" version (where Peters gets to be Prime Minister for part of a term) which in my view is totally unrealistic.

However, I now see that Peters has a workable strategy to get there in a certain scenario.

It may be unlikely, it may come to nothing - but Winston Peters has a plan to become Prime Minister.